This document explains how to implement on SAP a very simple kanban system to procure materials from vendors.
Kanban system is a “smart” system that could be used for example to procure materials with low value and a short lead-time. This kind of materials need to be procured when is requested and without added cost of management. Kanban system call the procurement when requested directly from shop-flor without any MRP run and the purchase order could be sent directly to the vendor.
To complete the solution we developed a Web-dynpro Abab forms. They are used directly on the shop-flor from the vendors itself (when they arrive weekly):
- Kanban change status – from FULL to EMPTY
- Good-receipt from Purchase Order
In order to set-up the kanban system is necessary to create a Kanban replenishment Strategy from tcode OM12. In order to manage better the message, we created a Purchase order type ZKB. The Purchase Order ZKB has a setting on message conditions to send the from by mail to the vendor address.
Master Data activities
To set-up the kanban is necessary to create the following Master Data:
- Production Supply Area that will contains the kanban – tcode PK05
- Set the MRP Storage Location Indicator to 1 – Material Master Data – from view MRP4 – tcode MM02
- Create Kanban Control Cycle from tcode PKMC
Control Cycle Kanban
From PKMC is necessary to mantain the Control Cycle Kanban.
Insert at list: material, Production Supply Area, Kanban Qty, No Kanban, WM info. Than External procurement type, vendor.
The kanban Quantity could be fixed initially with a nr 2 pcs. Than with the specific Kanban Calculation procedure is possibile to calculate the kanban no based on requirements.
In Kanban Calculation tab is possible to enter some parameters to calculate the number of kanbans or the kanban quantity (calculation type 1 or 2 rispectively).
Insert the Production Supply areas to select the requirements for Kanban Calculation.
The Kanban Calculation procedure will read the requirements on inserted Producion Supply Area and will determine the kanban nr with the following formula.
K = kanban nr
RT = Lead-Time (from Kanban Cycle or if missing from material master data)
AC = Average Consimption
CONT = Qty of material in a Kanban
SF = Safety Factor (default 1)
C = Cycle Control constant
Is possible to calculate the nr kanban (or the kanban quantity depending on calculation type into control cycle) from the tcode PK07 and PK08.
PK07 = create proposal
PK08 = display the proposals and update the kanban control cycles
Consider that the proposals could be created reading consumption/requirements from MRP or from LTP scenario.
When the Control cycles are created is necessary to print the kanban by PK17. Than is necessary to initialize them from kanban board PK13N.
Is very important to link the kanban printing with the box and update the kanban status from PK13N. This operation need to be done directly in the shop-flor and is a good exercise to train the people on kanban management. This operation need to be done accurately.
Procurement by kanban
We created a Web-Dynpro ABAP to manage the following processes:
- Change kanban status from FULL to EMPTY (WDA uses the BAPI_KANBAN_CHANGESTATUS1)
- Good-receipt against PO (WDA uses the BAPI_GOODSMVT_CREATE)
The WDA are used from vendors itself.
Otherwise you can use from classic GUI the tcode PKBC and read directly the barcode on Kanban printing (standar layout) to change the kanban status and MIGO to book the Good-receipt.